Abstract :
Many innovative industrial materials like carbon fibers, metal matrix composites MMC., hypereutectic AlrSi alloys are
very hard and difficult to machine with traditional cutting tools. CVD diamond coated inserts seem to be the most promising
system to overcome the problem. The WC, xCo hard metal, a widespread used and cheaper bulk material, could be a
convenient substrate for diamond film coatings. The Co-rich binder phase, however, constitutes a severe obstacle for
diamond deposition and adhesion, owing to its catalytic effect for amorphous carbon or soot formation. Several chemical and
physical methods have been developed to etch Co from the surface; however, no definite and reliable procedure has been
achieved. In our experiments, we treated the WC, xCo hard metal substrates with ArF ls193 nm, hns6.4 eV.and CO2
ls10.6 mm, hns0.12 eV.pulsed lasers, at different fluences and incident angles, to modify both the chemical
composition and the structure of the surfaces. The morphological and chemical effects have been studied by SEMrEDAX
microscopy and XPS surface analysis. Diamond nucleation and adhesion are compared with results obtained on the plain
tool substrates. q1999 Elsevier Science B.V. All rights reserved.
